I believe Kymoco's battery swap is the way to go.
It eliminates the time lag to charge a battery. Thus making the technology compete with liquid fossil fuels.
As I have explained in the past, I had proposed such a concept in 1980 with an electric car built around a battery exchange system. The battery pack was a tray (on casters) that held ten @ 12 volt standard batteries. Easy to exchange, rebuild and improve. The car was built around a central tube that contained the battery pack.. Push a fresh pack in the front, and the expended pack goes out the back. Fuel stations would simply plug them to chargers for reuse.
The car would have been built by Sebring, a manufacturer of kit cars, sold by Sears, and the battery system owned and operated by Shell Oil. After two years of negotiations, the deal fell thru when gasoline prices dropped to a dollar a gallon.
And,,,;
The fueling companies had begun to eliminate fuel station attendants by going to self-service.
Swapping the battery had several bonuses.
1) The battery was owned by the energy provider thus removing it's cost from the vehicle purchase price.
2) It allowed for battery technology to improve as the batteries were independently owned by an energy provider. Free market forces would have incentivized the battery provider(s) to compete and improve.
3) The five-minute exchange process would have competed with fossil re-fueling and allow for home charging as well.
However, I was a just little guy with an idea that didn't fly. Talking to big corporations that had no vision.